Optimized hydrogen production from a hydrocarbon

Abstract

A process for manufacturing a dihydrogen-containing outlet gas, including injecting a hydrocarbon inlet gas into a reactor, an operation of cracking the inlet gas with a three-phase plasma torch, and then delivering the outlet gas. The manufacture is carried out from injecting the inlet gas into the reactor to delivering the outlet gas, without either the inlet gas or the outlet gas undergoing expansion.

1 . A process for manufacturing a dihydrogen-containing outlet gas, comprising injecting a hydrocarbon inlet gas into a reactor with a plasma torch, an operation of cracking the inlet gas with the plasma torch, and then delivering the outlet gas, wherein the manufacture is carried out from injecting the inlet gas into the reactor to delivering the outlet gas, without either the inlet gas or the outlet gas undergoing an expansion greater than 20%, the plasma torch being supplied with three-phase current and the operation of cracking the inlet gas being carried out with a plasma a carrier gas of which is a mixture comprising hydrogen and/or hydrocarbons, the process comprising at least one separation operation carried out downstream of the cracking operation in order to separate the outlet gas from a solid carbon product, part of the outlet gas being used, downstream of a separation operation, in the carrier gas. 
     
     
         2 . The process according to  claim 1 , wherein the injection of the inlet gas is carried out under an injection pressure, greater than or equal to 4 bar. 
     
     
         3 . The process according to  claim 1 , comprising compressing to an injection pressure, upstream of the injection into the reactor. 
     
     
         4 . The process according to  claim 1 , comprising a filtering operation carried out downstream of the separation operation so as to produce a purified outlet gas with a higher concentration of dihydrogen than the outlet gas. 
     
     
         5 . The process according to  claim 4 , wherein the purified outlet gas is stored, at an operating pressure greater than or equal to the injection pressure. 
     
     
         6 . The process according to  claim 5 , wherein the purified outlet gas is stored, at an operating pressure strictly higher than the injection pressure. 
     
     
         7 . The process according to  claim 1 , wherein the filtering operation produces, in addition to the purified outlet gas, hydrocarbon gas which is reinjected into the reactor. 
     
     
         8 . The process according to  claim 1 , wherein the inlet gas is CH 4 . 
     
     
         9 . The process according to  claim 8 , wherein the part of the outlet gas used in the carrier gas comprises CH 4 . 
     
     
         10 . The process according to  claim 1 , wherein a plasma torch is used which is continuously fed with electrodes tightly to pressure variations within the reactor, without stopping manufacturing the outlet gas. 
     
     
         11 . A device for manufacturing a dihydrogen-containing outlet gas, comprising an injection line for a hydrocarbon inlet gas, into a reactor comprising a plasma torch configured to produce a cracking operation of the inlet gas and a delivery line for the outlet gas, the device being configured so that the inlet gas transits from its injection into the reactor until it is returned as outlet gas, without undergoing an expansion greater than 20%, the plasma torch being supplied with three-phase current and the device being configured so that the operation of cracking the inlet gas is carried out with a plasma a carrier gas of which is a mixture comprising hydrogen and/or hydrocarbons, the device comprising a separator located downstream of the reactor and configured so as to allow separation of the gas mixture at the outlet of the reactor into an outlet gas and a solid carbon product, and so that part of the outlet gas is reinjected into the carrier gas. 
     
     
         12 . The device according to  claim 11 , wherein the injection line comprises a plurality of injection holes oriented in distinct and radial directions with respect to a flow direction of a carrier gas in the reactor. 
     
     
         13 . The device according to  claim 11 , comprising an inlet compressor of the inlet gas placed on the injection line. 
     
     
         14 . The device according to  claim 11 , wherein the plasma torch comprises electrodes configured to be fed continuously and tightly to pressure variations inside the reactor. 
     
     
         15 . The device according to  claim 11 , said device being tight to pressure variations, from the injection line, into the reactor until it is returned from the outlet gas. 
     
     
         16 . The device according to  claim 11 , comprising an outlet compressor downstream or upstream of a storage element, configured to rise the outlet gas in pressure from a delivery pressure to an operating pressure. 
     
     
         17 . The device according to  claim 11 , comprising a pumping system on a recirculation line of the part of the outlet gas. 
     
     
         18 . The device according to  claim 11 , comprising a heat exchanger upstream of the separator and downstream of the reactor. 
     
     
         19 . The device according to  claim 18 , wherein the heat exchanger is a gas-gas exchanger where the fresh gas is at least part of the inlet gas.